1. Field of Invention
The present invention relates to the general art of watercraft, and to the particular field of hybrid-electric powered watercraft incorporating manual (pedal, human) power with electric power amplification via electric battery storage and solar energy coupled via control electronics.
2. Description of Prior Art
A multitude of pedal-powered watercraft (also referred to as water bikes, water-bicycles, and watercycles) are commercially available. They are relatively low cost, low maintenance, light weight, and fun. Their main drawback is the relatively low power output capability of the operators. Unlike watercraft propelled by conventional combustion engines, pedal-powered watercraft are severely limited in power capability; typically less than 200 watts (around ¼ hp) per person on a continuous basis. A cyclist in good condition can generate around 200 watts at a preferred cadence of around 90-100 RPM. Many people of lesser abilities may be only capable of generating around 100 watts in a continuous comfortable manner. Thus maximizing the overall efficiency of the watercraft, including its propulsion system, as it travels in water is vitally important to maximize speed and travel distance capabilities. To maximize the speed (and pedaling efficiency), many of the newer watercycles such as the Seacycle® and Waterbike® manufactured by the Meyers Boat Company, Inc., are designed to be as light-weight with efficient long and narrow hulls.
The patented prior art has included numerous designs of pedal-powered watercraft. However, many of the recent inventions have had the primary object to improve transportability by car. For example:
U.S. Pat. No. 5,088,944 (Kats) discloses a collapsible water bike consisting of two pontoons and driven by a pedal assembly connected to a propeller via a gear unit. A handlebar connected to a rudder provided steering. The object was to enable ease of transportation without need of special tools or transporting vehicle such as a truck.
U.S. Pat. No. 5,217,398 (Meron et al) discloses a pedal operated catamaran, including an elongated, longitudinal drive shaft connected to a propeller. A gear train transmits power from the pedal crankshaft to the propeller drive shaft. A latching mechanism allows on-the-fly adjustment of the propeller position, thereby facilitating car top carrying of the watercraft without disassembly, and adjusting for varying water conditions.
U.S. Pat. No. 5,362,264 (Parant) discloses a water-bicycle comprising an elongated flotation board, and an easily detachable propulsion and seat unit, with the propeller unit passing through the board. A detachable handlebar connected to a rudder also passes through the board and enables steering.
Pedal-powered watercraft designs tend to be the result of a compromise between the conflicting objectives of weight, cost, seaworthiness, transportability, comfort, and speed.
U.S. Pat. No. 5,722,865 (Tatum) discloses a canard balanced marine bicycle that significantly improves upon the weight and speed vs. seaworthiness compromise. The canard provides dynamic stability enabling the watercraft to have a single long, slender lightweight hull, thereby improving the efficiency, and resulting speed, in the water. However, the propulsion power, and hence, ultimate speed and travel distance, is still limited by the capabilities of the individual rider.
U.S. Pat. No. 6,217,398 B1 (Davis) discloses a human-powered or human-assisted energy generation and transmission system with energy storage means and improved efficiency. The generation and transmission system is intended to be an improvement over conventional mechanical systems, such as pedal-powered systems comprising chains and sprockets, by controlling the energy output to be constant, independent of the pedal position, thereby claiming to improve the overall efficiency. Over a typical pedal cycle, the power produced by a human varies substantially with pedal position. According to the Davis invention, energy storage is used to supplement the human power during the portion of the pedaling cycle that is least efficient. This portion of the pedal cycle is determined by sensors detecting the pedal position during rotation. The supplemental energy is extracted from the energy generated during the portion of the pedaling cycle that is most efficient, such that the average energy generated and used for propulsion is not increased, apart from potential claimed efficiency improvements. The generation and transmission system consists of electric generators, motors, energy storage, controllers, and sensors, without mechanical linkages. The intended applications are human-powered or human-assisted vehicles of all types, including bicycles, watercraft, aircraft, hydrofoils, and hovercraft.
Numerous all-electric pleasure watercraft are also commercially available. These watercraft typically contain lead-acid battery storage and DC electric motor propulsion. Electric trolling motors are commonly used for the electric motor propulsion units. The primary limitations of these electric watercraft are finite range and speed.
Objects and Advantages
The object of the invention is to provide a pleasure watercraft that is simultaneously lightweight, low cost, environmentally friendly with zero pollution, ultra-low noise, and thrilling to operate, while simultaneously providing an optional means of enjoyable exercise for operators of all abilities. A person that routinely pedals a conventional watercycle on a specific lake or river is likely to see only the same limited area each time, due to the severely restricted speed, and hence, travel distance possible within a finite amount of exercise time. This can lead to boredom rapidly. Thus one objective of the present invention is to provide a new type of watercycle employing a human power-amplification means via energy storage to substantially increase the speed and range of the watercraft.
This invention combines human-power and electric-power watercraft technologies into one watercraft, and by adding new innovative controls, the best of both types of watercraft is obtained. With this invention, the fit cyclist that routinely exercises, as well as the occasional rider, can explore a much larger area of a bay, lake or river, in a shorter amount of time, thereby increasing enjoyment considerably. Unlike battery-only electric watercraft, this invention removes the worry of running out of battery power, or solar power on a cloudy day or night., If the batteries become drained, and solar power is not available, the operator can still pedal back to shore, though at reduced power. Diagnostic displays that monitor the usable stored energy of the battery, as well as the generated solar power and pedal power, keep the operator informed, so that the operator can wisely return to shore under full power, if desired, prior to battery depletion.
Another objective of the present invention is to provide a watercraft comprising a widely variable electronic gearing ratio, enabling the operator to independently set the pedaling cadence and power level, thereby maximizing the efficiency and comfort of the operator.
It is another objective of the present invention to provide a watercraft comprising human power-amplification and variable electronic gearing ratio, thereby permitting operators of differing physical abilities and goals to simultaneously operate one or more of the watercraft over the same distance at the same speed, thereby sharing the experience, while still exercising at their individually preferred effort levels.
It is another objective of the present invention to provide a dual-seated watercraft comprising dual systems of human power-amplification and variable electronic gearing ratio, thereby permitting operators of differing physical abilities and goals to simultaneously operate the same watercraft while each independently achieving their desired level of physical exercise, without sacrificing the overall speed or travel distance of the watercraft.
It is still another objective of the present invention to provide a watercraft comprising operator-selectable pedal torque vs. pedal cadence characteristics, such as simulated rolling hills, a simulated mechanically-coupled water propeller, or a simple linear characteristics, to add an additional degree of enjoyment and pedaling comfort to the operator. Such flexibility is not possible with pure mechanically-driven systems, such as prior art waterbikes.
Yet another objective of the present invention is to provide a watercraft employing a human power-amplification means via energy storage with photovoltaic power to recharge the energy storage, thereby providing a pollution-free watercraft.
Yet another objective of the present invention is to provide a watercraft employing a human power-amplification means via energy storage with photovoltaic power to enable increased travel speed and range when the energy storage system is depleted.
Yet another objective of the present invention is to provide an electric watercraft that can be optionally operated solely from stored energy or on-board photovoltaic power.